Chronic hyperglycemia in patients with type II diabetes can lead to a variety of complications including nephropathy and retinopathy. One of the major pathophysiological mechanisms by which hyperglycemia may lead to characteristic irreversible tissue damage is the formation of glucose-derived cross links in proteins (advanced glycated endproducts [AGE's]) that result in increased stiffness, abnormal protein accumulation, membrane leakiness and dysfunction. Patients with diabetes have been shown to have higher levels of serum AGE's than nondiabetic subjects, and the AGE levels are proportional to the severity of diabetic nephropathy. Also, reactive intermediates formed during periods of hyperglycemia may continue to cross-link with proteins even after blood glucose is lowered. Therefore, normalization of blood glucose may not completely prevent the progression of complications, and a pharmacologic agent, such as pimagedine, may be of significant benefit in the treatment of such patients. The purpose of this study is to assess the efficacy (and safety), with regard to retarding to progression of diabetic nephropathy, of inhibiting the formation of AGE with pimagidine. Patients in this study are initially randomized to either a placebo or one of two levels of pimagide; however, patients' dosage may be changed during the course of the study, based on individual need. Each patient is routinely evaluated every several months for blood pressure, hemoglobin A1c (HbA1c), kidney function, and general chemistry and hematology profile. Additionally, the patients have a Glomerular Filtration Rate test every 3 months and a dilated eye exam yearly. To date, the only therapies available to the physician to prevent the progression of diabetic nephropathy are normal blood pressure control and normal blood sugar control; however, these therapies indirectly impede nephropathy. Pimagedine may be the first pharmacologic therapy to directly prevent the progression of diabetic nephropathy. This study has been designed to accumulate information regarding the safety and efficacy of pimagedine over a 3 to 4 year period. If this study shows a positive safety and efficacy profile future studies may ensue. Because this is a blinded study in progress there are no results nor conclusions to report.